CS258235B1 - A method of producing one-component polyolefin filter-drainage bellows - Google Patents

Abstract

The invention concerns single-component polyolefin filtration and drainage fleeces, whereby the conditions are chosen such that randomly arranged polyolefin fibers with a diameter of 0.1 to 2.0 mm simultaneously form a filtration layer with a fiber diameter of 0.1 to 0.5 mm and a drainage layer with a fiber diameter of 0.5 to 2 mm, and their mutual ratio is in the range of 10 to 90%, whereby the fibers are point-bonded in a thermoplastic state at the point of mutual intersection.

Description

258235 2

The present invention relates to single-component polyolefin drainage webs with filtering and drainage function.

So far known embodiments of these systems are based on the use of fiber-material combinations that are bonded either mechanically, chemically, or combined by both methods, e.g. podlá čel. AO 227 164. It is known to produce filter-drainage staple fibers of polyolefin fibers in which the drainage function itself determines the elevated or otherwise-bonded second drainage component to a base filter layer made, for example, by a web-forming technique directly under the spinneret. In the tomtosystem, a synthetic lattice or polyolefin non-oriented fiber fabrics produced directly under the spinneret can be used as a drainage layer. These methods are used by foreign manufacturers, eg Lotrak resp. Miradrain.

Said systems require a demanding production process, namely the production of a basic filtration drainage layer, and in a further process they are interconnected into a filter-drainage system, these processes being demanding on machinery, manufacturing areas and workforce. In addition, when the drainage and filtration layers are bonded mechanically or chemically, the internal drainage layer is damaged, thereby reducing the technical parameters of the original components. At the same time, when using a combination of staple and continuous polyolefin fibers interconnected mechanically, undesirable deformations occur when applied, as these webs are not self-supporting in the vertical position.

The essence of the function of the filter-drain pipes is that these webs are able to supply the liquid to the drainage tube itself, and are also resistant to soil fouling.

The aforementioned drawbacks are solved by the present invention, according to which a single-component polyolefin filter drainage system is produced such that randomly arranged polyolefin fiber diameters from 0.1 to 2.0 mm in the thermoplastic state are point-connected, with the fibers of the upper fineness prevailing in the center of the cross-flow filter fleece. the center of the system, the drainage layer is protected from both sides by the filter layer, where the fiber is at the lower end of the range. In this way, one-component filtration-drainage fleece can be produced by one technological operation by means of a suitable spinning nozzle arrangement of one spinning system with different nozzle diameters, different number of capillaries on one spinneret nozzle, adjustment of temperature regime and polymer melt dispensing, making this production easier compared to known systems.

In principle, this method of production uses a device for the production of a bonded surface fiber formation directly under the spinning nozzle according to the Czechoslovak Act. No. 133,524, the novelty being the use of a single fiberising system for forming fibers of different fineness deposited in a one-component filtration system in one technological process.

No. 133,524, for this purpose, contemplates the use of two sets of spinnerets arranged one behind the other.

Compared to the above Czechoslovak. The patent allows this method of producing filter-drainage tubes to produce further modifications with a different filter-drainage ratio.

For the production of a single-component polyolefin filtration fleece, high-pressure polyethylene with a flow index of 170 to 220 g / min. 1 min., Or spun-forming polypropylene with a flow index of 35 to 40 g / min. May also be used as a starting material. with melt index min. 90 g.

The filter mat according to the invention is shown in the following examples and the filter layer 1 with the drainage layer 2 is shown in section.

Claims (1)

Process for producing single-component polyolefin filter-drainage webs by direct production technology under a spinneret such that the polyolefin fibers are spatially arranged at a point of intersection in a thermoplastic state, interconnected in a thermoplastic state, characterized in that in one technological operation they utilize a single spinneret a diameter of 0.1 to 2.0, whereby a filter layer (1) with a fiber diameter of 0.1 to 0.5 mm and a drainage layer (2) with a fiber diameter of 0.5 to 2.00 mm and a weight ratio to each other are formed is in the range of 10 to 90 4.